Former NASA training specialist Shannon O'Roark Griffin and her husband Roscoe, a decorated retired Air Force colonel, appeared to be the picture of a committed couple working on bumps in their marriage - even attending counseling together near their home in Kansas.

But in a counseling session on Friday Mr. Griffin, 52, revealed a dark secret that would shatter their marriage. Police say he told his wife he was having an affair with a psychiatrist - 46-year-old Dr. Irina Puscariu - but he refused to end it.

Police say Mr. Griffin said he wanted a divorce, and Mrs. Griffin walked out of the session and snapped. Police documents paint a picture of a vengeful woman who told her husband he was "not the first person Irina Puscariu would hurt and would not be the last" - a far cry from the woman she appears to be in a serene Facebook photo.

Detectives say that after the counseling session Mrs. Griffin drove 250 miles to Puscariu's home, outside Kansas City, Mo., and rang her doorbell. Once inside, she shot the doctor three times in the face. Puscariu's mother, with whom she lived, saw her daughter get shot, police said.

Afterwards Griffin called her daughter to tell her she had committed murder. Puscariu's neighbors were shocked.

"I was really scared, because I didn't know if it was a random death or something personal," said one neighbor.

Police documents reveal while on the run, Mrs. Griffin had several conversations with her husband, admitting his mistress was dead and telling him she did what had to be done to "protect him and others from this evil woman."

Roscoe Griffin called his mistress' home only to learn it was true. Cell phone GPS led police to Mrs. Griffin on a Kansas highway, where she was pulled over. She reportedly told police she had two unloaded handguns in her car.

Mrs. Griffin is currently in jail in Kansas, facing first-degree murder charges.